Electrically charged fencing is often used to fence in animals, or to prevent animals from accessing certain areas. In order to provide insulation between electrified wires and support posts, dielectric brackets can be used. However, such brackets are prone to breakage, and can be expensive. As an alternative, tubular insulators are available. However, such tubular insulators require that each insulator be threaded onto the associated wire. This can result in a time consuming and inconvenient process, particularly where long runs of fencing are being installed, or where existing fencing is being repaired. It can also be desirable to add insulation to other electrical conductors. For example, vehicle trailers often include wiring that is exposed and prone to damage. In order to repair or protect such systems, tape can be applied. However, tape can be messy and unreliable. As another example, heat shrink tubing can be placed over wires and/or connectors. However, the use of such tubing requires that wires be broken or disconnected in order to place the wire in the tubing.